The Soviet Union famously churned out tens of thousands of new apartment buildings in the 1960s, ’70s, and ’80s — some assembled in as little as 12 days — together comprising tens of millions of individual apartments. Such speed is not unique to communist command economies, or even to grim concrete mega-blocks. In Sweden and Japan today, modern, high-quality new homes can be factory-built and assembled in a matter of weeks using the same basic method — prefabrication — as the Soviets.

The US, alas, evinces no such urgency to build housing. 

In some of our highest-cost cities — San Francisco, New York, Miami — it takes, somewhat astonishingly, nearly five years to erect a modestly sized apartment building, from the time an application is first submitted to building completion. That was one of the top-line findings of a remarkable new economics working paper on housing construction timelines across 60 US cities. The gaps between the fastest and slowest cities were just as striking: In Raleigh, North Carolina, a builder can complete a 20-unit apartment building in about as much time as it takes just to approve the permit for one in San Francisco, where applications languish for more than a year. In Indianapolis, a single-family home can be built in six months from proposal to completion, less than one-eighth the time it takes in San Francisco.

Such delays have costs — in delayed housing supply at a time when America is millions of homes in the hole, in lost staff time that developers ultimately bake into the cost of the new homes, and in homes that simply never get built because the process is discouraging to anyone but the best-resourced developers. The authors, Leonardo D’Amico, Evan Soltas, and Audrey Wang, found that longer permitting lengths are correlated with higher housing prices and lower rates of housing production, though they don’t claim to have shown that these are causal relationships. The research (which has not yet been through peer review and, like any working paper, may be revised before final publication) represents the first such comprehensive dataset comparing homebuilding timelines across the US. To build it, the researchers assembled 1.1 million permits covering 2.7 million housing units between 2000 and 2025 — about one in 13 new homes permitted nationally over that period, they write. 

It probably won’t come as a shock to you that housing can be built faster in Sioux Falls, South Dakota, than in Los Angeles or pretty much anywhere in California. But perhaps the most notable takeaway (to me, anyway) from the paper was how massively home permitting times have lengthened across the board over the past 25 years. Across the cities in their sample, the researchers estimate that permitting time for a standardized multifamily building rose from 0.6 years in 2000 to 1.5 years in 2023, and, for a single-family home, from 1.6 months in 2000 to 4.9 months in 2023. 

Is there really any good reason why we should take nearly a year longer to approve an apartment building than, Soltas joked in a recent interview, “the barbarians of 2006”? Shouldn’t we be getting faster and more efficient at building housing over time, not slower — especially at a time of acute housing scarcity? 

You would think. So what is going on here?

One building, very different wait times

Permitting refers to everything that happens after a developer submits an application to build a house or multifamily building, before they’re allowed to break ground. The proposal is then reviewed for compliance with a range of different sets of rules, from building safety and energy codes to plumbing to zoning and, in some places, aesthetic design. Initial applications will often be found noncompliant and then sent back to the builder for revisions, Soltas, an assistant professor of economics at Princeton, told me.  

The gulf between housing starts in California and Texas has become something of a meme in housing abundance circles. But, for all that, we have until now lacked rigorous apples-to-apples comparisons of permitting and building times in different metro areas, Soltas said. That gap in seemingly basic knowledge, what should be “step zero” facts for the national housing reform debate, became apparent to him when he was teaching an urban economics class, which became one of the impetuses for the new paper. “I realized if I needed that information to teach my students, that it might be useful for other people,” he said. 

Rather than merely pulling permits from different cities and comparing how long whatever happened to be built in each city took to approve, the researchers used the data to estimate how long an identical, standardized project would take in each place between 2015 and 2019, keeping constant its size and the density of the surrounding neighborhood. Their uniform archetypes were a 2,800-square-foot detached single-family home on a 0.15-acre lot and a 20-unit multifamily building with 1,200 square feet per apartment.

Cities with longer permitting times also tended to have longer construction periods — the longer it takes to get an application approved, the longer it then takes to do the building itself, which compounds the gap between the fastest- and slowest-building cities (it’s possible that “cities that make the permitting process difficult also put in lots of burdens that slow the construction process,” Soltas said). One advantage of the researchers’ method is that the differences across cities can’t merely be chalked up to something like the complexity of building within already-dense environments like Manhattan — the analysis already controls for that. So the enormous gaps between different places become harder to dismiss as inevitable features of development in big cities.

The study wasn’t designed to answer the “why” of it all — those will be questions for future research. “Our paper doesn’t directly identify any smoking guns,” Soltas said. Still, some of the culprits are likely obvious — California, for example, has long subjected some housing projects to extensive environmental review requirements under the California Environmental Quality Act (CEQA). Apartment buildings, especially larger ones, are more likely to have to go through CEQA review, though they’re more environmentally friendly than single-family homes (recognizing this as an obstacle to housing affordability, California has been moving to exempt many housing projects from such reviews). 

Why are we taking so much longer to permit housing?

But why, as the study finds, is permitting becoming slower across the country, not just in the most regulated cities? “We estimate that, in 2000, our standardized multi-family project had a 71-percent probability of approval within six months of applying for a permit,” the researchers write. “In 2025, that project had a 44-percent approval probability within six months.” Permitting times have come down a bit since 2023, but it’s unclear whether that just represents the reversal of pandemic-era highs, or if it reflects real progress from the pro-housing policies that have been passed in many cities and states in recent years. 

That discovery dovetails with other economics research finding that zoning codes, which were first widely adopted in the US in the early-to-mid 20th century, have continued to become more restrictive even in recent years, making it harder to build housing. 

Without knowing why exactly permitting lengths have ballooned, it’s hard to say whether those increases have occurred for good reasons. At least some of it may have to do with the aforementioned intensification of zoning and other land-use restrictions, which, I can say from having written a lot about zoning, tend to be pretty ill-conceived and hard to justify. 

The slowdown may also be connected to expanding building code requirements. I’ve written at length about that issue, too; although ever-more stringent rules might seem like a great idea — who could be opposed to more safety? — they tend to be biased against multi-family housing and likely inflate the cost of building, all without having to show that the benefits are worth the costs. Particularly the cost in housing supply that never gets built, which has the effect of keeping more Americans living in older housing stock. And do we really think a home built to 2005 standards is dangerously subpar today?  

We might ultimately decide that many of today’s building requirements — particularly ones like stronger energy efficiency standards — are worth it, but first we’d need to determine what their full costs are, which we remain far from doing. 

At a minimum, it seems unlikely that an apartment building that’s okay to build in Grand Rapids today would be unsafe for New York. So what, exactly, is all that extra permitting time buying the city? Now, at least, Mayor Zohran Mamdani can put an exact number on the delay. 

This story appeared in Today, Explained, a daily newsletter that helps you understand the most compelling news and stories of the day. Subscribe here.

Today’s newsletter is a heavy one — so please feel free to skip it if you need to. But as the uproar over an alarming rape allegation at Cornell University from 2024 keeps building, I wanted to take a minute to look at the facts of the case and the wider scourge of campus sexual assault. (We’ll get into that second topic in just a minute.)

You’ve probably read about the case on social media, but if not, let me bring you up to speed. A former Cornell undergraduate student, identified as Jane Doe in a civil lawsuit filed earlier this month, alleges that seven men pressured her into drinking and snorting large amounts of ketamine, an anesthetic that can cause dissociation, before raping her at a campus fraternity house.

At the time, she reported the incident to campus police — but her lawsuit alleges the men were never adequately investigated. Instead, the case was handled through Cornell’s administrative disciplinary system, which meted out noncriminal punishments, such as suspensions and expulsions, and permanently shuttered the fraternity house.

The case and its handling have horrified observers online and in Ithaca, New York, where Cornell is located. In response to that uproar, the Tompkins County district attorney announced on Monday that he was reopening his office’s investigation. A nine-page statement further explained why the DA’s office didn’t file criminal charges two years ago: At the time, the statement says, the woman did not allege that she was incapacitated or that the encounter was nonconsensual. 

For many online, however, that explanation only prompted more questions, such as: Was Jane Doe ever interviewed by a specialist trained to speak to survivors? And what prompted her to go to police in the first place, if she believed the encounter was consensual? The reopened investigation will take time, but should provide some answers.

Go a little deeper

Sexual assault remains appallingly common on college campuses. When I taught an undergraduate writing class in 2024, I assigned my students a personal essay and encouraged them to choose a topic they found weighty or meaningful. In a class of 11 women, two wrote about being assaulted at school. 

That proportion surprised and horrified me, though it shouldn’t have. Surveys have consistently estimated that roughly one in five undergraduate women experiences some form of sexual assault or nonconsensual contact during college. 

Awareness around the issue has grown over the past decade or so, particularly in light of the Me Too movement and after a string of high-profile cases in the mid-2010s. But progress has been more complicated.

First, it’s difficult to know if the situation is improving or worsening, because the data around campus sexual assault is really limited. Federal law has historically required that universities disclose only the incidents reported through official channels — a small minority of all cases. 

In 2022, Congress enacted a requirement directing colleges and universities to begin conducting more comprehensive surveys on campus sexual assault every two years. That would have helped measure the true scope of the problem — arguably, a prerequisite for designing and tracking potential interventions. But the Biden administration never set up that survey, and President Donald Trump has, if anything, rolled back college sexual assault protections and slow-walked Title IX investigations related to sexual harassment and violence.

Just Monday, in fact, Trump’s Department of Education formally rescinded Biden-era rules designed to better hold schools accountable for sexual assault. The department will now revert to rules put in place during Trump’s first term, which defined sexual harassment more narrowly and gave schools more latitude over how they handle allegations. 

It’s an amazing irony, really, that those rollbacks were formalized on the same day that prosecutors reopened the Cornell case. If anything, the outrage over that investigation shows that people want institutions to take sexual assault more seriously. 

One link for later

➨ Make art a little more personal. The average museumgoer looks at any one piece of art for only 27 seconds — maybe because it’s daunting to spend any more time on the task of Serious Art Appreciation. Instead of laboring to interpret a piece the “right” way, try relating it to your personal experience and other cultural objects you know well. This is also a correct and valid way to look at art! As one artist told Vox, “I don’t need the viewer of my paintings to know exactly what I meant…it’s more about an openness to a conversation.” 

Before you go…

• Did you know…that the sun’s magnetic north and south poles reverse roughly every 11 years? It generally doesn’t have much of an impact on Earth, though it can make the auroras more visible. 
• Today’s trivia: The civil rights activist Ruby Bridges became famous at age 6 for doing what? (You can find this and other brain puzzles in Vox’s daily crossword. Look for the answer in tomorrow’s edition.)
• Yesterday’s trivia: We asked you for the name of the unrequited love interest in Victor Hugo’s The Hunchback of Notre Dame. That would be Esmeralda, whose fate was way darker in the 1831 novel than in the Disney movie version.